Multiple magnetic transitions and anomalous magnetism in Tb2CuGe3

We report the formation of a compound, Tb2CuGe3, in a AlB2-derived hexagonal structure and its magnetic characteristics by electrical resistance (1.4-300 K), magnetization (2-300 K) and heat-capacity (2-50 K) measurements. The results establish that there is an onset of antiferromagnetic ordering at a temperature close to 19 K, which is much larger than the de Gennes scaled value. The data also present evidence for additional magnetic transitions at lower temperatures, say at about 13 and 8 K, which also appear to be of antiferromagnetic type, however, with possible differences in the Fermi surfaces/magnetic structure. These results characterize that this compound is an interesting magnetic system. (C) 2001 Elsevier Science Ltd. All rights reserved.